1. Field of the Invention
This invention relates to grinding devices and more particularly to adaptors for grinders for the fitting of new, different inside diameter water main receiving-openings of fire hydrants to existing piping and water main systems.
2. Prior Art
Replacement of aging fire hydrants is commonplace in about every community throughout the country. The fire hydrant itself is a valving device which is connected to a buried water main. Such water mains are typically made from cast iron and are expensive to replace, and often lasting many more years than any hydrant which it serves. Those mains are typically buried relatively deeply in the ground, to prevent them from freezing. These mains may have a pipe extending to the ground surface with a valve below the frost line. Most hydrants are connected to a main, by a six inch pipe. However, a proper mating between the hydrant and the main is frequently time consuming and expensive to facilitate. Often, the municipality will cut a nipple out of ductle iron in order to fit it to the hydrant. Thereafter they may install a repair sleeve which must be tied back using threaded rods, eye bolts and locking gland.
It is an object of the present invention to overcome the disadvantages of the prior art.
It is a further object of the present invention to provide a jig arrangement which is attachable to hydrants, gates, and offsets to permit the grinding off of an inner circumference of hydrant material so as to permit a proper fit with the outer circumferential ring of the pre-existing water main to which it should mate.
It is still yet a further object of the present invention to permit the use of newer hydrants with the existing older water main which may be readily and inexpensively relined, compared to the cost of replacing them by the mere adaptation of those old lines to the proper enlargable inner opening sizing of the newer hydrants.